JP7846527B2 - Control device for gripping-type hole-digging and pole-erecting vehicle - Google Patents

Description

The present invention relates to a control device for a gripping-type hole-digging and pole-erecting vehicle equipped with a gripping device for gripping, for example, columnar objects.

One type of work vehicle known as a hole-digging and pole-erecting vehicle is a gripping-type hole-digging and pole-erecting vehicle, which is equipped with a slewing platform that is rotatably mounted on the vehicle body, a boom that is rippled and extendable on the slewing platform, an auger device attached to the boom for digging holes for erecting utility poles, and a gripping device provided at the tip of the boom for gripping columnar objects such as utility poles (see, for example, Patent Document 1). When digging a pole-erecting hole in the ground using this gripping-type hole-digging and pole-erecting vehicle, the boom is operated as appropriate with the auger device suspended from the tip of the boom, and the auger device is rotated at a predetermined digging position to form a pole-erecting hole of a predetermined depth. After the excavation of the pole-erecting hole is completed, the auger device is raised and stored on the side of the boom, and the utility pole is gripped by the gripping device provided at the tip of the boom. With the utility pole being gripped, the boom is operated as appropriate to directly erect the utility pole into the excavated pole-erecting hole. This type of gripping-type hole-digging and pole-erecting vehicle allows for more efficient pole-erecting operations compared to methods that involve suspending utility poles using winches or cranes.

Japanese Patent Application Publication No. 2-81892

However, when inserting a utility pole held by the gripping device into the mounting hole, it was difficult for the worker to visually adjust the pole to a vertical position aligned with the vertical direction, posing a challenge that required skilled operation from the worker.

This invention has been made in view of the above problems, and aims to provide a control device for a gripping-type hole-digging and pole-erecting vehicle that can change a columnar object gripped by the gripping part to a desired vertical position without requiring the skilled operating abilities of the operator.

To solve the above problems, the control device for a gripping-type hole-digging pole-erecting vehicle according to the present invention comprises: a boom mounted on the vehicle body so as to be able to move up and down and extend and retract; a gripping part for gripping a columnar object; a support mechanism provided between the tip of the boom and the gripping part to change the posture of the gripping part relative to the tip of the boom; a gripping part inclination angle detector for detecting the inclination angle of the gripping part with respect to the horizontal plane; an operating device for operating the boom, the gripping part and the support mechanism; and an operation control unit for controlling the operation of the boom, the gripping part and the support mechanism in accordance with the operation of the operating device. The operating device has an automatic vertical operating device for positioning a columnar object gripped by the gripping part in a vertical position along the vertical direction, and the operation control unit is characterized in that , when the angle of inclination of the gripping part with respect to the horizontal plane detected by the gripping part inclination angle detector is within a predetermined angle, the automatic vertical operating device is operated, and the support mechanism is activated according to the angle of inclination of the gripping part with respect to the horizontal plane detected by the gripping part inclination angle detector to change the position of the gripping part, thereby controlling the columnar object gripped by the gripping part to be in a vertical position.

In the control device for the gripping type hole-digging pole-erecting vehicle with the above configuration, the gripping part has a pair of openable and closable gripping claws for gripping a columnar object, the support mechanism has a swivel mechanism for swinging the gripping part in a vertical plane, and a rotation mechanism for rotating the gripping part in the vertical plane around a rotation axis perpendicular to the opening and closing direction, and the operation control unit preferably changes the posture of the gripping part to a vertical posture by operating the swivel mechanism according to the angle of inclination of the gripping part in the direction of the rotation axis with respect to the horizontal plane, as detected by the gripping part inclination angle detector, and operating the rotation mechanism according to the angle of inclination of the gripping part in the opening and closing direction with respect to the horizontal plane.

According to the control device for the gripping-type hole-digging pole-erecting vehicle of the present invention, when the automatic vertical operation device is operated, the support mechanism is activated according to the inclination angle of the gripping part relative to the horizontal plane detected by the gripping part inclination angle detector, thereby changing the posture of the gripping part. This allows the columnar object gripped by the gripping part to be positioned vertically along the vertical direction. Therefore, even on sloping ground such as in mountainous areas, the columnar object gripped by the gripping part can be automatically positioned vertically without requiring skilled operation, dramatically improving the efficiency of pole-erecting work.

This is a side view of the gripping type hole-digging and pole-erecting vehicle according to this embodiment. The above is a plan view of the gripping-type hole-digging and pole-erecting vehicle. This is a side view showing the usage of the gripping-type hole-digging and pole-erecting vehicle described above. This is a perspective view of the auger device installed on the gripping-type hole-digging and pole-erecting vehicle described above. This is a perspective view of the gripping device provided on the gripping-type hole-digging and pole-erecting vehicle described above. This is a perspective view of the main part of the gripping device shown above, taken from the right. This is a perspective view of the main part of the gripping device shown above, taken from the left. This is a cross-sectional view of the gripping device described above. This is a longitudinal cross-sectional view of the gripping device described above. This is a side view of the pole removal device installed on the gripping-type hole-digging pole-erecting vehicle described above. The above is a functional block diagram of the gripping-type hole-digging and pole-erecting vehicle. This is a schematic diagram illustrating the operation of positioning the gripping portion of the above-mentioned gripping device in a horizontal position. This is a conceptual diagram illustrating the relationship between the load acting on the gripping part and the amount of displacement when the gripping part is moved vertically downward. This is a schematic diagram illustrating the excavation work of the gripping-type hole-digging and pole-erecting vehicle shown above. This is a schematic diagram showing the operation of the gripping part when the automatic vertical switch provided on the gripping type hole-digging and pole-erecting vehicle described above is operated. This is a schematic diagram illustrating the direction of the load acting on the gripping part during the process of inserting the utility pole, which is gripped by the gripping part, into the pole installation hole. This is a schematic diagram showing the flow of automated pole removal work using the above-mentioned pole removal device. This is a schematic diagram showing the flow of automated pole erection work using the above-mentioned pole removal device (a continuation of Figure 17 above). This is a schematic diagram showing the flow of automated pole erection work using the above-mentioned pole removal device (a continuation of Figure 18 above).

The following describes preferred embodiments of the present invention with reference to the drawings. First, the overall configuration of the gripping-type hole-digging and pole-erecting vehicle 1 according to this embodiment will be described with reference to Figures 1 to 3.

The gripping-type hole-digging and pole-erecting vehicle 1, as shown in Figure 1, is based on a truck vehicle with a driver's cabin 7 at the front of the vehicle body 2 and a pair of left and right tires 5 positioned at the front and rear of the vehicle body 2. Jacks 9 are provided at four locations on the front, rear, left, and right sides of the vehicle body 2 to lift and support it. Each jack 9 lifts and supports the vehicle body 2 by driving a jack cylinder (not shown) located inside it to extend downwards, thereby stabilizing the entire vehicle body 2. The operation of the jacks 9 is performed by operating a jack operating device (not shown) located at the rear of the vehicle body 2.

In the mounting area behind the driver's cabin 7 on the vehicle body 2, a slewing platform 12 is provided, which is driven by a slewing motor 14 (see Figure 11) and is configured to rotate horizontally around its vertical axis. The base end of the boom 13 is attached to this slewing platform 12 so as to be able to swing (raise and lower) in the vertical direction.

The boom 13 has a structure in which the base boom 13a, intermediate boom 13b, and tip boom 13c are nested together in order from the turntable 12 side. The boom 13 can be extended and retracted axially (longitudinal direction) by the extension and retraction drive of the telescopic cylinder 15 (see Figure 11) located inside. Furthermore, a luffing cylinder 16 is mounted between the base boom 13a and the turntable 12, and by driving the extension and retraction of this luffing cylinder 16, the entire boom 13 can be raised and lowered within the vertical plane.

The boom 13 is fitted with an auger support 17 that can be selectively connected to the base boom 13a and the tip boom 13c. As shown in Figure 4, the upper shaft portion 27a of a connecting rod member 27 is pivotally connected to the auger support 17 so as to be able to swing in the left-right direction. An auger device 20 for excavating a pole hole is pivotally connected to the lower shaft portion 27b of the connecting rod member 27 so as to be able to swing in the front-rear direction. The auger device 20 consists of an auger motor section 21 pivotally connected to the lower shaft portion 27b of the connecting rod member 27, and an auger screw (earth auger) 25 that rotates around its axis when the auger motor section 21 is operated. The auger motor section 21 has an auger motor 22 that rotates hydraulically, an auger reducer 23 connected to the output shaft of the auger motor 22, and an auger housing 24 that houses the auger motor 22 and the auger reducer 23. A drive shaft (not shown) of the auger reducer 23 protrudes from the lower end of the auger housing 24, and the upper end of the auger screw 25 is connected to this drive shaft.

Furthermore, an auger storage device 18 is provided on the side of the base boom 13a to hold the auger device 20 in a stored position. The auger device 20 is attached to the auger support 17 via a connecting rod member 27 so as to be able to swing up and down in a vertical plane. It is possible to swing the auger device 20 between a stored position, where it is stored along the side of the base boom 13a by the auger storage device 18, and a working position, where the auger device 20 is detached from the auger storage device 18 and the auger screw 25 is suspended towards the ground. Note that, when in the working position, the auger device 20 is suspended from the tip of the boom 13 so as to be able to swing freely in the front-rear and left-right directions, using the two shaft portions 27a and 27b of the connecting rod member 27 as pivot points, so that the auger screw 25 maintains a vertical position along the direction of gravity (vertical direction), regardless of the orientation of the boom 13.

When using the auger device 20, as shown in Figure 3I, the auger support 17 is connected to the tip boom 13c, and the auger device 20, which has been detached from the auger storage device 18, is swung to the working position (with the auger screw 25 in a position approximately perpendicular to the ground). The auger screw 25 is rotated by the rotational drive of the auger motor 22, and the boom 13 is moved linearly downward in conjunction with its lowering and retracting operations, thereby enabling the excavation of pole holes. On the other hand, when the auger device 20 is not in use, as shown in Figure 3II, the auger support 17 is connected to the base boom 13a, and the auger device 20 is stored and held in a storage position along the side of the base boom 13a by the auger storage device 18. When the auger device 20 is in the storage position, various operations such as pole erection and removal of utility poles (indicated by the symbol P in Figure 3; the same applies hereafter) and obstacle relocation can be performed using the gripping device 50 described later.

An arm bracket 19 is fixed to the tip of the boom 13c. A gripping device 50, which grips objects (columnar objects) such as utility poles or trees, is attached to this arm bracket 19. The configuration of this gripping device 50 will be explained with additional reference to Figures 5 to 9. Note that in Figures 8 to 9, the hatching indicating the cross-section has been omitted for clarity. Furthermore, for the sake of explanation, the orientation of the gripping device 50 shown in Figure 5 will be used as the reference point, and the directions indicated by the front/back, left/right, and up/down arrows will be referred to as the front/back direction, left/right direction, and up/down direction, respectively.

The gripping device 50 comprises an arm 51 mounted on an arm bracket 19 so as to be able to swing (flex and extend) vertically, a first joint member 60 mounted on the tip of the arm 51 so as to be able to swing (vertical pivot) vertically, a second joint member 70 mounted on the first joint member 60 so as to be able to swing (lateral pivot) horizontally, and a gripper 80 rotatably mounted on the second joint member 70. In this embodiment, a support mechanism for changing the posture of the gripping portion 81 of the gripper 80 is configured using the arm 51, the first joint member 60, the second joint member 70, the vertical pivot cylinder 62 (described later), the horizontal pivot cylinder 71, the gripper motor 79, etc.

The arm 51 is pivotally connected to the arm bracket 19 at one end in the axial direction (longitudinal direction) via a connecting pin 52, and its other end in the axial direction (longitudinal direction) is pivotally connected to the first joint member 60 via a connecting pin 53. An arm cylinder 55 is mounted between the arm bracket 19 and the arm 51. The rod-side end of the arm cylinder 55 is pivotally connected to the arm bracket 19 via a connecting pin 56. The bottom-side end of the arm cylinder 55 is pivotally connected to the tip side of the arm 51 via a connecting pin 57. By extending and retracting this arm cylinder 55, the arm 51 is configured to swing freely (flex and extend freely) in the vertical direction around the connecting pin 52 relative to the arm bracket 19.

The first joint member 60 is formed in a bifurcated shape with an open tip, and the second joint member 70 is pivotally connected to both ends of this bifurcated shape via a pair of upper and lower connecting pins 61. A vertical swivel cylinder 62 is provided between the first joint member 60 and the arm 51. The bottom end of the vertical swivel cylinder 62 is pivotally connected to the base end of the arm 51 via a connecting pin 63. The rod end of the vertical swivel cylinder 62 is pivotally connected to the upper end of the first joint member 60 via a connecting pin 64. By extending and retracting this vertical swivel cylinder 62, the first joint member 60 is configured to swing freely (vertically swivel) in the vertical direction around the connecting pin 53 relative to the arm 51.

The second joint member 70 is supported by the first joint member 60, sandwiched between it from above and below. A lateral swivel cylinder 71 is provided at the upper end of the first joint member 60. The bottom end of the lateral swivel cylinder 71 is pivotally connected to the tip of the first joint member 60, and the rod end is pivotally connected to the rear end of the second joint member 70. By extending and retracting this lateral swivel cylinder 71, the second joint member 70 is configured to swing freely (swivel freely) in the left-right direction around the connecting pin 61 relative to the first joint member 60.

The gripper 80 comprises a gripping portion 81 for gripping an object, a gripper housing 86 rotatably mounted on the second joint member 70 to support the gripping portion 81, and an opening/closing mechanism 93 for opening and closing the gripping portion 81.

The gripping section 81 comprises a pair of gripping claws 82 and a pair of upper and lower support plates 83 that support the pair of gripping claws 82 so that they can open and close in directions toward or away from each other (opening and closing directions). The gripping claws 82 are configured to grip various objects (columnar objects) such as utility poles and trees. The base ends of the gripping claws 82 are pivotally connected to the upper and lower support plates 83 via connecting pins 84. The tips of the gripping claws 82 have alternating notches 82a and 82b, and these tips are configured to intersect (overlap) with each other. The support plates 83 are provided with a flat upper bracket 85 for detachably attaching an attachment (not shown, for example, a tree felling device).

The gripper housing 86 comprises a support cylinder portion 87 connected to the upper and lower support plate portions 83 and rotatably supported by the second joint member 70, and a cylinder bracket portion 92 fixed to the base end of the support cylinder portion 87 and disposed between the first joint member 60 and the second joint member 70.

The support cylinder portion 87 has a double structure, comprising an inner cylinder portion 88 formed in the shape of a hollow rectangular tube, and an outer cylinder portion 89 formed in the shape of a hollow cylindrical tube and provided on the outer circumference of the inner cylinder portion 88. A sliding member 95 of the opening/closing mechanism 93, described later, is attached to the inner circumference of the inner cylinder portion 88 so as to be slidable in the front-rear direction. A worm wheel 90 is attached to the outer circumference of the outer cylinder portion 89 concentrically with the outer cylinder portion 89. This worm wheel 90 meshes with a worm pinion 91 that is rotatably supported inside the second joint member 70. A gripper motor 79 is attached to the upper end of the second joint member 70, and the worm pinion 91 is connected to the output shaft of this gripper motor 79 via a reduction gear. When this gripper motor 79 is rotated in the forward direction, the entire gripper 80 rotates in a predetermined direction around the rotation axis X (see Figure 8) via the worm pinion 91 and worm wheel 90. On the other hand, when the gripper motor 79 is rotated in the reverse direction, the entire gripper 80 rotates in the opposite direction to the predetermined direction around the rotation axis X (see Figure 8) via the worm pinion 91 and worm wheel 90. In the orientation of the gripping device 50 shown in Figure 5, the rotation axis X direction of the gripper 80 (gripping portion 81) corresponds to the front-to-back direction, and the opening and closing direction (gripping direction) of the gripping portion 81 corresponds to the left-to-right direction.

The opening/closing mechanism 93 comprises a pair of link members 94, a sliding member 95 linked to the pair of link members 94, and a gripper cylinder 99 that slides the sliding member 95 back and forth. One end of each link member 94 is pivotally connected to the middle part of the gripping claw 81 via a connecting pin 96. The other ends of the pair of link members 94 are also pivotally connected to the tip of the sliding member 95 via a connecting pin 97, with the other ends of each link member 94 overlapping vertically. The sliding member 95 is inserted into the hollow part of the inner cylindrical portion 88 and is mounted so as to be slidable (reciprocal) along the inner circumferential surface of the inner cylindrical portion 88. A slider 98 made of synthetic resin is attached between the outer circumferential surface of the sliding member 95 and the inner circumferential surface of the inner cylindrical portion 88 to guide the sliding (reciprocating) movement of the sliding member 95. The rod-side end of the gripper cylinder 99 is connected to the base end of the sliding member 95. The bottom end of the gripper cylinder 99 is connected to the cylinder bracket portion 92 of the gripper housing 86. When the gripper cylinder 99 is extended, the sliding member 95 slides in the extension direction, causing the link members 94 to swing away from each other. As a result, the gripping claws 82 swing in the opening direction with the connecting pin 84 as a pivot point (the gripping claws 82 operate in the opening direction), releasing the grip on the object. On the other hand, when the gripper cylinder 99 is retracted, the sliding member 95 slides in the retraction direction, causing the link members 94 to swing towards each other. As a result, the gripping claws 82 swing in the closing direction with the connecting pin 84 as a pivot point (the gripping claws 82 operate in the closing direction), gripping the object. The opening and closing mechanism 93 is configured symmetrically, so the pair of gripping claws 82 open and close symmetrically.

On the side of the turntable 12 in the vehicle body 2, there is an operator's seat 30 for operating each work device (turntable 12, boom 13, auger device 20, gripping device 50). In front of this operator's seat 30, there is an operating device 31 that can be operated by the operator while seated. As shown in Figure 11, the operating device 31 includes a boom rotation/luffing lever 32a for rotating and luffing the boom 13, a boom extension/retraction/bending lever 32b for extending and retracting the boom 13 and bending the arm 51, an auger operating lever 32c for rotating the auger screw 25, a gripper vertical swing lever 32d for vertical swinging the gripper 81, a gripper horizontal swing lever 32e for horizontal swinging the gripper 81, a gripper rotation lever 32f for rotating the gripper 81, and a gripper opening/closing lever 32g for opening and closing the gripper 81.

Furthermore, the operating device 31 is provided with a pole-pulling machine operating lever 32h for operating the pole-pulling machine 40, which is used as an optional hydraulic device (for pulling out utility poles). As shown in Figure 10, the pole-pulling machine 40 is composed of a pole-pulling machine cylinder 41 that extends and retracts hydraulically, a base plate 44 provided at the lower end of the pole-pulling machine cylinder 41 and grounded, and a chain 45 that is locked to the upper end of the pole-pulling machine cylinder 41 and wrapped around a utility pole (indicated by the symbol P in Figure 10). The pole-pulling machine cylinder 41 is composed of a cylinder tube 42 and a piston rod 43 that is assembled to the cylinder tube 42 so as to be extendable and retractable in the vertical direction. Both ends of the chain 45 are detachably locked to the upper end of the cylinder tube 42 of the pole-pulling machine cylinder 41. The chain 45 is formed to a length that allows it to be wrapped around the outer circumference of the utility pole several times. A base plate 44 is pivotally attached to the lower end of the piston rod 43, allowing it to swing freely around a support shaft 44a (allowing it to swing according to the slope and unevenness of the ground). Furthermore, the pole-removing machine cylinder 41 is connected to a hydraulic hose 46 that connects to the bottom oil chamber of the cylinder tube 42, and a hydraulic hose 47 that connects to the rod-side oil chamber of the cylinder tube 42. By connecting these hydraulic hoses 46 and 47 to a hydraulic outlet for the pole-removing machine (not shown) provided on the vehicle body 2 using a sealed coupling (one-touch joint), the oil chambers of the pole-removing machine cylinder 41 (bottom oil chamber, rod oil chamber) and the ports of the electromagnetic proportional control valve V10 are connected via this hydraulic outlet, enabling the supply and discharge of hydraulic fluid (pressurized oil) between the pole-removing machine cylinder 41 and the electromagnetic proportional control valve V10.

Furthermore, as shown in Figure 11, the operating device 31 is equipped with a mode selection switch 33, an automatic vertical switch 34, and an automatic column removal switch 35.

The mode selection switch 33 is a toggle switch that can be switched to one of the following positions: neutral, forward, or backward (it is configured to retain the selected operating position even if the operator releases their hand). When the mode selection switch 33 is selected to the neutral position, the normal mode is set; when the mode selection switch 33 is selected to the forward position, the auger vertical operation mode is set; and when the mode selection switch 33 is selected to the backward position, the gripping unit vertical operation mode is set. The normal mode is a mode in which each hydraulic actuator is operated independently in response to the operation of each operating lever 32a to 32h, allowing for individual luffing, extension, and slewing of the boom 13, rotation of the auger device 20 (auger screw 25), bending and extending of the arm 51, vertical swivel, horizontal swivel, rotation, and opening/closing of the gripping unit 81, and extension and retraction of the column removal machine 40. The auger vertical operation mode is a mode in which the luffing cylinder 16 and the telescopic cylinder 15 are operated in combination (interlocked operation) in response to the operation of the boom slewing and luffing operation lever 32a, thereby moving the auger device 20 (the tip of the boom 13) vertically (up and down). The gripping section vertical operation mode is a mode in which the luffing cylinder 16, the telescopic cylinder 15, and the vertical swivel cylinder 62 are operated in combination (interlocked operation) in response to the operation of the boom slewing and luffing operation lever 32a, thereby moving the gripping section 81 vertically (up and down).

The automatic vertical switch 34 is configured as a toggle switch that can be switched between an ON position and an OFF position (it is configured to maintain the switched operating position even when the operator releases their hand). When the automatic vertical switch 34 is selected in the ON position, as will be described in detail later, the vertical swivel cylinder 62 and the gripper motor 79 are activated to cause the gripping part 81 to swivel vertically and rotate, thereby allowing the gripping part 81 to be positioned horizontally (that is, the utility pole gripped by the gripping part 81 can be made vertical). Note that the automatic vertical switch 34 becomes active (the operation signal is effectively received) when the inclination angle of the gripping part 81 with respect to the horizontal plane, as detected by the gripping part inclination angle detector 124 (see Figure 11), is within a predetermined angle.

The automatic pole removal switch 35 is configured as a toggle switch that can be switched between an ON position and an OFF position (it is configured to retain the switched operating position even when the operator releases their hand). When the automatic pole removal switch 35 is selected in the ON position, as will be described in detail later, the gripper cylinder 99 and the pole removal machine cylinder 41 are operated in conjunction, and by combining the opening and closing operation of the gripping part 81 and the extension and retraction operation of the pole removal machine 40, the pole removal work of pulling the existing utility pole out of the ground can be performed automatically.

Here, the operating mechanisms of the turntable 12, boom 13, auger device 20, gripping device 50, and pole removal machine 40, as shown in Figure 11, are configured with a controller 100 that receives operation signals from the operating device 31 and controls the turntable motor 14, telescopic cylinder 15, luffing cylinder 16, auger motor 22, arm cylinder 55, vertical swivel cylinder 62, horizontal swivel cylinder 71, gripper motor 79, gripper cylinder 99, and pole removal machine cylinder 41 (hereinafter collectively referred to as "hydraulic actuators"), and a hydraulic unit 110 that supplies hydraulic fluid to drive these hydraulic actuators.

The operation signal output by the operation device 31 is input to the controller 100. The controller 100 outputs a command signal corresponding to that operation signal to the hydraulic unit 110 (control valve 112).

The hydraulic unit 110 comprises a hydraulic pump 111 that discharges hydraulic fluid and control valves 112 that control the direction and amount of hydraulic fluid supplied from the hydraulic pump 111 to each hydraulic actuator. The hydraulic pump 111 is driven by power taken from the vehicle's engine via a PTO mechanism (not shown). The control valves 112 include an electromagnetic proportional control valve V1 corresponding to the swing motor 14, an electromagnetic proportional control valve V2 corresponding to the telescopic cylinder 15, an electromagnetic proportional control valve V3 corresponding to the luffing cylinder 16, an electromagnetic proportional control valve V4 corresponding to the auger motor 22, an electromagnetic proportional control valve V5 corresponding to the arm cylinder 55, an electromagnetic proportional control valve V6 corresponding to the vertical swing cylinder 62, an electromagnetic proportional control valve V7 corresponding to the horizontal swing cylinder 71, an electromagnetic proportional control valve V8 corresponding to the gripper motor 79, an electromagnetic proportional control valve V9 corresponding to the gripper cylinder 99, and an electromagnetic proportional control valve V10 corresponding to the pole removal cylinder 41. Based on command signals from the controller 100, this control valve 112 electromagnetically drives the spools of each electromagnetic proportional control valve V1 to V10 to control the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 111 to each hydraulic actuator, and controls the operating direction and operating speed of each hydraulic actuator (turntable 12, boom 13
(This controls the operating direction and operating speed of the auger device 20, gripping device 50, and column removal machine 40.)

The controller 100 is electrically connected to various detectors, including a boom luffing angle detector 120, a boom extension amount detector 121, a boom slewing angle detector 122, an auger tilt angle detector 123, a gripping section tilt angle detector 124, a gripping section load detector 125, a gripper cylinder pressure detector 126, and column extraction machine cylinder pressure detectors 127 and 128.

The boom luffing angle detector 120 is installed within the base boom 13a and detects the luffing angle of the boom 13. The boom extension amount detector 121 is installed at the base end of the base boom 13a and detects the length (extension amount) of the boom 13. The boom slewing angle detector 122 is installed on the vehicle body 2 and detects the slewing angle of the boom 13 (slewing body 12).

The auger tilt angle detector 123 is mounted on the upper part of the auger motor unit 21 (auger housing 24). This auger tilt angle detector 123 detects the tilt angle of the auger device 20 (auger screw 25). Here, as described above, the auger device 20 is suspended from the tip of the boom 13 so as to be able to swing back and forth and left and right with the two shaft portions 27a and 27b of the connecting rod member 27 as fulcrums, so that the auger screw 25 takes a vertical position along the direction of gravity (vertical direction) regardless of the position of the boom 13. Therefore, when the auger device 20 is excavating a hole for erecting a pole (indicated by the symbol "K" in Figure 14), if the excavation resistance of the ground is large, the axis of the auger screw 25 may tilt back and forth and left and right with respect to the vertical line (vertical direction). The auger tilt angle detector 123 is composed of a two-axis tilt angle detector that detects the tilt angle of the auger screw 25 in the left-right direction (X-axis direction) and the tilt angle in the front-back direction (Y-axis direction) relative to the vertical direction. This auger tilt angle detector 123 detects the left-right and front-back tilt angles of the auger screw 25 and outputs a voltage signal (detection signal) corresponding to the detected tilt angle to the controller 100.

The gripping section tilt angle detector 124 is mounted on the upper surface of the gripping section 81 (support plate section 83). This gripping section tilt angle detector 124 is a two-axis tilt angle detector that detects the tilt angle of the gripping section 81 with respect to the horizontal plane, specifically the tilt angle in the left-right direction (X-axis direction) and the tilt angle in the front-back direction (Y-axis direction). The gripping section tilt angle detector 124 detects the left-right and front-back tilt angles of the gripping section 81 and outputs a voltage signal (detection signal) corresponding to the detected tilt angle to the controller 100.

The gripping section load detector 125 is a so-called pin-type load cell and is configured as the connecting pin 63 that pivotally connects the bottom end of the vertical swivel cylinder 62 and the base end of the arm 51. This gripping section load detector 125 detects the axial load (the axial direction of the vertical swivel cylinder 62) acting on the connecting pin 63 from the vertical swivel cylinder 62 and outputs a voltage signal (detection signal) corresponding to the detected load to the controller 100. The load detected by this gripping section load detector 125 (the load acting on the connecting pin 62) is proportional to the load acting on the gripping section 81 (the load the gripping section 81 receives in the vertical plane). Therefore, as will be described in detail later, the controller 100 determines the load acting on the gripping section 81 based on the load detected by this gripping section load detector 125.

The gripper cylinder pressure detector 126 is installed in the oil passage connecting the electromagnetic proportional control valve V9 and the rod- side oil chamber of the gripper cylinder 99, and detects the pressure of the hydraulic fluid supplied to the rod- side oil chamber of the gripper cylinder 99 (pressure in the rod- side oil chamber). The gripper cylinder pressure detector 126 detects the pressure in the rod-side oil chamber of the gripper cylinder 99 and outputs a voltage signal (detection signal) corresponding to the detected pressure to the controller 100. The pressure detected by the gripper cylinder pressure detector 126 is proportional to the gripping force of the gripping part 81 (the force with which the gripping part 81 grips an object). Therefore, as will be described in detail later, the controller 100 determines the gripping force of the gripping part 81 based on the pressure detected by the gripper cylinder pressure detector 126.

The column removal machine cylinder pressure detector 127 is installed in the oil passage connecting the electromagnetic proportional control valve V10 and the bottom oil chamber of the column removal machine cylinder 41, and detects the pressure of the hydraulic fluid supplied to the bottom oil chamber of the column removal machine cylinder 41 (pressure in the bottom oil chamber). The column removal machine cylinder pressure detector 128 is installed in the oil passage connecting the electromagnetic proportional control valve V10 and the rod-side oil chamber of the column removal machine cylinder 41, and detects the pressure of the hydraulic fluid supplied to the rod-side oil chamber of the column removal machine cylinder 41 (pressure in the rod-side oil chamber). These column removal machine cylinder pressure detectors 127 and 128 detect the pressure of the hydraulic fluid supplied to each oil chamber (bottom oil chamber, rod-side oil chamber) of the column removal machine cylinder 41 and output a voltage signal (detection signal) corresponding to the detected pressure to the controller 100. In this embodiment, the stroke end in the extension/retraction direction of the column removal machine cylinder 41 is detected based on the pressure detected by the column removal machine cylinder pressure detectors 127 and 128.

The controller 100 comprises a position calculation unit 101, an operation control unit 102, an auger inclination determination unit 103, a gripping determination unit 104, an automatic vertical control unit 105, a load determination unit 106, and an automatic column removal control unit 107.

The position calculation unit 101 calculates the position of the tip of the boom 13 relative to the vehicle body 2 based on detection information from the boom luffing angle detector 120, the boom extension amount detector 121, and the boom slewing angle detector 122.

The operation control unit 102 controls the operation of each actuator according to the operation signals (operation commands) output from the operating device 31, based on the operation mode selected by the mode selection switch 33. The operation modes are described below.

(Normal mode)
When the mode selection switch 33 is selected for normal mode, the operation control unit 102 operates each hydraulic actuator independently in response to the operation of each of the operation levers 32a to 32h. Specifically, when the boom slewing/luffing operation lever 32a is tilted forward (in the forward, backward, left, and right directions relative to the operator operating it; the same applies hereinafter), the luffing cylinder 16 is retracted to lower the boom 13, and when the boom slewing/luffing operation lever 32a is tilted backward, the luffing cylinder 16 is extended to raise and lower the boom 13. Also, when the boom extension/bending operation lever 32b is tilted forward, the extension cylinder 15 is extended to extend the boom 13, and when the boom extension/bending operation lever 32b is tilted backward, the extension cylinder 15 is retracted to retract the boom 13. Furthermore, when the boom slewing/luffing lever 32a is tilted to the left, the slewing motor 14 is operated in the forward direction to slewing the boom 13 counterclockwise, and when the boom slewing/luffing lever 32a is tilted to the right, the slewing motor 14 is operated in the reverse direction to slewing the boom 13 clockwise. Also, when the auger operation lever 32c is tilted forward, the auger motor 22 is operated in the reverse direction to rotate the auger screw 25 in the reverse direction, and when the auger operation lever 32c is tilted backward, the auger motor 22 is operated in the forward direction to rotate the auger screw 25 in the forward direction. Furthermore, when the boom extension/bending operation lever 32b is tilted to the left, the arm 51 is operated to bend downward relative to the tip of the boom 13, and when the boom extension/bending operation lever 32b is tilted to the right, the arm 51 is operated to bend upward relative to the tip of the boom 13. Furthermore, when the gripping unit's vertical swivel operation lever 32d is tilted forward, the vertical swivel cylinder 62 is extended to swing the gripping unit 81 downward (vertical swivel), and when the gripping unit's vertical swivel operation lever 32d is tilted backward, the vertical swivel cylinder 62 is retracted to swing the gripping unit 81 upward (vertical swivel). Also, when the gripping unit's horizontal swivel operation lever 32e is tilted to the left, the horizontal swivel cylinder 71 is extended to swing the gripping unit 81 to the left (horizontal swivel), and when the gripping unit's vertical swivel operation lever 32e is tilted to the right, the horizontal swivel cylinder 71 is retracted to swing the gripping unit 81 to the right (horizontal swivel). Furthermore, when the gripping section rotation lever 32f is tilted forward, the gripper motor 79 is operated in the forward direction to rotate the gripping section 81 clockwise, and when the gripping section rotation lever 32f is tilted backward, the gripper motor 79 is operated in the reverse direction to rotate the gripping section 81 counterclockwise. Also, when the gripping section opening/closing lever 32g is tilted forward, the gripper cylinder 99 is operated in the retraction direction to operate the gripping section 81 in the closing direction (direction for gripping the object), and when the gripping section opening/closing lever 32g is tilted backward, the gripper cylinder 99 is operated in the extension direction to operate the gripping section 81 in the opening direction (direction for releasing the grip of the object). Furthermore, when the pole removal machine operating lever 32h is tilted forward, the pole removal machine cylinder 41 is extended to extend the pole removal machine 40, and when the pole removal machine operating lever 32h is tilted backward, the pole removal machine cylinder 41 is retracted to retract the pole removal machine 40.

(Auger vertical operation mode)
Furthermore, when the boom slewing and luffing operation lever 32a is operated while the mode selection switch 33 is selected for auger vertical operation mode, the operation control unit 102, based on the position information (current position) of the tip of the boom 13 calculated by the position calculation unit 101, combines and operates the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15 in a linked manner, and moves the auger screw 25 (tip of the boom 13) vertically in accordance with the operation of the boom slewing and luffing operation lever 32a. Specifically, when the boom slewing and luffing operation lever 32a is tilted forward, the auger screw 25 is moved vertically downward by combining the retraction of the luffing cylinder 16 and the retraction of the telescopic cylinder 15, and when the boom slewing and luffing operation lever 32a is tilted backward, the auger screw 25 is moved vertically upward by combining the extension of the luffing cylinder 16 and the extension of the telescopic cylinder 15.

(Grip section vertical operation mode)
Furthermore, when the mode selection switch 33 is selected for the gripping unit vertical operation mode and the boom slewing and luffing operation lever 32a is operated, the operation control unit 102, based on the position information (current position) of the tip of the boom 13 calculated by the position calculation unit 101 and the tilt angle of the gripping unit 81 detected by the gripping unit tilt angle detector 124, combines and operates the extension and retraction of the luffing cylinder 16, the extension and retraction of the telescopic cylinder 15, and the extension and retraction of the vertical swivel cylinder 62 in an interlocking manner, thereby moving the gripping unit 81 (the object gripped by the gripping unit 81) in the vertical direction in response to the operation of the boom slewing and luffing operation lever 32a. Specifically, when the boom slewing and luffing operation lever 32a is tilted forward, the gripping portion 81 is moved vertically downward by combining the retraction operation of the luffing cylinder 16, the retraction operation of the telescopic cylinder 15, and the retraction operation of the vertical swivel cylinder 62. When the boom slewing and luffing operation lever 32a is tilted backward, the gripping portion 81 is moved vertically upward by combining the extension operation of the luffing cylinder 16, the extension operation of the telescopic cylinder 15, and the extension operation of the vertical swivel cylinder 62. Specifically, the vertical operation control of the gripping section 81 is performed by combining two controls: one that moves the tip of the boom 13 vertically by combining the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15, based on the position information of the tip of the boom 13 calculated by the position calculation unit 101; and another that maintains the gripping section 81 (the rotation axis X of the gripping section 81) in a horizontal state by extending and retracting the vertical swivel cylinder 62, based on the detection information (the angle of inclination of the gripping section 81 with respect to the horizontal plane) detected by the gripping section inclination angle detector 124.

The auger tilt determination unit 103, based on the detection information from the auger tilt angle detector 123,
The orientation of the auger device 20 (auger screw 25) is determined. Specifically, the auger tilt determination unit 103 compares the tilt angle of the auger screw 25 detected by the auger tilt angle detector 123 with a preset allowable angle (threshold angle) to determine whether the tilt angle of the auger screw 25 exceeds the allowable angle. The tilt angle of the auger screw 25 is the angle at which the axis of the auger screw 25 is tilted in the front, back, left, and right directions relative to the vertical direction. For example, 5 degrees is set as the allowable angle (however, this can be arbitrarily changed). Here, in the auger vertical operation mode, when an excavation operation is performed that combines the rotational operation and vertical descent operation of the auger screw 25, if the auger tilt determination unit 103 determines that the tilt angle of the auger screw 25 is within the allowable angle, it permits the excavation operation. If it determines that the tilt angle of the auger screw 25 exceeds the allowable angle, it outputs a restriction signal to the operation control unit 102 to restrict the excavation operation. When the auger tilt determination unit 103 inputs a restriction signal to the operation control unit 102, the operation control unit 102 blocks the control signals to the control valve 112 that cause the auger screw 25 to rotate and to descend vertically, thereby forcibly stopping the auger screw 25's excavation operation. This prevents the auger screw 25 from excavating at an angle exceeding the allowable angle (resulting in the pole hole being formed at an angle). At this time, the auger screw 25's excavation operation (rotation and vertical descent) is restricted, but the operation of moving the auger screw 25 vertically upward from the pole hole being excavated (vertical upward movement of the auger screw 25) is permitted. Therefore, if the auger screw 25's excavation operation is restricted, the auger screw 25 can be moved vertically upward and pulled out of the excavation hole, allowing its own weight to return it to a vertical position (facing vertically downward). After returning the auger screw 25 to a vertical position, the auger screw 25 can be rotated and lowered vertically again, allowing the excavation of the pole hole (the same pole hole) to be restarted from the middle.

The gripping determination unit 104 determines the gripping state of the gripping unit 81 based on the detection information from the gripper cylinder pressure detector 126. Specifically, the gripping determination unit 104 determines that the gripping unit 81 is gripping the utility pole (object) (i.e., the gripping unit 81 is gripping the utility pole with a specified gripping force) when the pressure detected by the gripper cylinder pressure detector 126 rises to or above a preset first threshold pressure. Furthermore, the gripping determination unit 104 determines that the gripping unit 81's grip on the utility pole (object) has been loosened (i.e., the gripping force has been reduced to the extent that the utility pole will not fall off the gripping unit 81) when the pressure detected by the gripper cylinder pressure detector 126 falls to or below a preset second threshold pressure (provided that the first threshold pressure is greater than the second threshold pressure).

When the automatic vertical switch 34 of the operating device 31 is turned ON, the automatic vertical control unit 105 determines whether the tilt angle of the gripping section 81 detected by the gripping section tilt angle detector 124 is within a predetermined angle (for example, within 5 degrees). The automatic vertical control unit 105 stores an automatic vertical program, and when it determines that the tilt angle of the gripping section 81 is within a predetermined angle when an operation signal is input from the automatic vertical switch 34, it outputs a command signal to the operation control unit 102 based on the detection information from the gripping section tilt angle detector 124, according to this automatic vertical program. When the operation control unit 102 receives a command signal from the automatic vertical control unit 105, it feeds back the tilt angle of the gripping unit 81 from the gripping unit tilt angle detector 124. Based on this feedback information, it extends and retracts the vertical swivel cylinder 62 until the tilt angle of the gripping unit 81 in the front-rear direction reaches the target angle (0 degrees) to correct the tilt of the gripping unit 81 in the front-rear direction, and rotates the gripper motor 79 until the tilt angle of the gripping unit 81 in the left-right direction reaches the target angle (0 degrees) to correct the tilt of the gripping unit 81 in the left-right direction. The tilt of the gripping unit 81 in the front-rear direction can be made by extending the vertical swivel cylinder 62 to tilt the gripping unit 81 downwards (see Y1 direction in Figure 12), and by retracting the vertical swivel cylinder 62 to tilt the gripping unit 81 upwards (see Y2 direction in Figure 12). Furthermore, regarding the left-right tilt of the gripping portion 81, the gripping portion 81 can be tilted to the left around the rotation axis X (see direction Z1 in Figure 12) by rotating the gripper motor 79 in the forward direction, and tilted to the right around the rotation axis X (see direction Z2 in Figure 12) by rotating the gripper motor 79 in the reverse direction. In this way, the operation control unit 102 performs feedback control based on the deviation between the tilt angle of the gripping portion 81 and the target angle (0 degrees) based on the command from the automatic vertical control unit 105, and sets the gripping portion 81 to a horizontal position (the utility pole gripped by this gripping portion 81 to a vertical position). Furthermore, this automatic vertical control is used not only when the gripping part 81 is in a horizontal position while gripping a utility pole (i.e., when the gripping part 81 is in a vertical position), but also when the gripping part 81 is in a horizontal position while not gripping a utility pole (i.e., when the gripping part 81 is not gripping anything). As a variation, the automatic vertical control unit 105 may be configured to perform automatic vertical control only when the gripping determination unit 104 has determined that the gripping part 81 is gripping a utility pole (object).

The load determination unit 106 determines the change in the load acting on the gripping part 81 based on the detection information from the gripping part load detector 125. Here, Figure 13 is a conceptual diagram showing the relationship between the load acting on the gripping part 81 and the displacement when the gripping part 81 is moved vertically downward. As shown in Figure 13, when the gripping part 81 is gripping the utility pole, a load corresponding to the weight of the utility pole acts downward on the gripping part (A in the figure). At this time, when the gripping part 81 is moved vertically downward and the lower end of the utility pole gripped by the gripping part 81 reaches the bottom of the hole for pole installation (B in the figure), the load acting on the gripping part 81 decreases due to the reaction force received from the bottom of this hole (a reaction force that tries to push the utility pole upward). Then, after the load on the gripping part 81 has decreased to 0 (C in the figure), the direction of the load reverses from downward to upward (D in the figure). Thus, the timing at which the utility pole contacts the bottom of the hole corresponds to the timing at which the direction of the load acting on the gripping part 81 reverses (the timing at which the load becomes 0). Therefore, when the gripping part 81 is gripping the utility pole, the load on the gripping part 81 detected by the gripping part load detector 125 during the vertical downward movement of the gripping part 81 decreases to a threshold load (0 in this embodiment), and the load determination unit 106 determines that the utility pole gripped by the gripping part 81 has contacted the bottom of the hole for pole installation. When the load determination unit 106 determines that the load detected by the gripping part load detector 125 has decreased to a threshold load (that the object has contacted the bottom of the hole for pole installation), it outputs a restriction signal to the operation control unit 102 to restrict the vertical downward movement (downward movement in the vertical direction) of the gripping part 81. When the operation control unit 102 receives a restriction signal from the load determination unit 106, it ignores the operation signal for vertical downward movement of the gripping part 81 among the operation signals input by the operation device 31, or blocks the control signal for vertical downward movement of the gripping part 81 among the control signals from the operation control unit 102 to the control valve 112, thereby forcibly stopping the vertical downward movement of the gripping part 81 that was being performed up to that point. As a result, even if further operation to move the gripping part 81 vertically downward (operation to move the utility pole downward) is performed, the vertical downward movement of the gripping part 81 is restricted. In this way, the downward movement of the gripping part 81 is restricted when the lower end of the utility pole contacts the bottom (back end) of the pole installation hole, thus preventing the lower end of the utility pole from being pressed excessively against the bottom of the hole.

When the automatic pole removal switch 35 of the operating device 31 is turned ON, the automatic pole removal control unit 107 operates the gripping unit 81 and the pole removal machine 40 in conjunction to perform an automatic pole removal operation to pull the existing utility pole out of the ground. This automatic pole removal operation includes the steps of releasing (releasing) the gripping unit 81 from its grip on the utility pole and extending the pole removal machine 40, and gripping the utility pole with the gripping unit 81 and retracting the pole removal machine 40. The automatic pole removal control unit 107 stores an automatic pole removal program, and when it receives an operation signal from the automatic pole removal switch 35, it outputs a command signal to the operation control unit 102 based on detection information from the gripper cylinder pressure detector 126 and the pole removal machine cylinder pressure detectors 127, 128, etc., in accordance with this automatic pole removal program, and controls the opening and closing operation of the gripping unit 81 and the extension and retraction operation of the pole removal machine 40 in conjunction to continuously execute each step of the automatic pole removal operation. Details of the column removal process (automatic column removal process) in this embodiment will be described later.

Next, the operation of the gripping-type hole-digging and pole-erecting vehicle 1 of this embodiment will be described. The following describes, in order, the excavation work, pole-erecting work, and pole-removal work using the gripping-type hole-digging and pole-erecting vehicle 1 of this embodiment.

[1. Excavation work]
First, let's explain the excavation work (hole digging operation) of the gripping-type hole-digging and pole-erecting vehicle 1. Figure 14 is a schematic diagram showing the excavation work by the auger device 20. Unless otherwise specified in the following explanation, the mode selection switch 33 is assumed to be in normal mode.

When performing excavation work with the gripping-type hole-digging and pole-erecting vehicle 1, first, the auger support 17 is connected to the tip boom 13c, and then the operating device 31 is operated to raise and lower the boom 13 by a predetermined angle (for example, 60 degrees). In this state, the auger device 20 is detached from the auger storage device and suspended vertically downward from the tip of the boom 13. Next, the operating device 31 is operated to raise, lower, extend, and rotate the boom 13 to move the auger screw 25 above the excavation position. Subsequently, the mode selection switch 33 is switched from normal mode to auger vertical operation mode, and while the auger screw 22 is rotated, the lowering and retracting operations of the boom 13 are linked to move the auger screw 25 vertically downward, thereby digging the ground vertically with the auger screw 25. At this time, as shown in Figure 14, if the ground being excavated is hard, the auger screw 25 (axis J) may tilt forward, backward, left, or right relative to the vertical direction due to the excavation reaction force (excavation resistance) from the ground. The tilt angle of the auger screw 25 is detected moment by moment by the auger tilt angle detector 123 provided on the upper surface of the auger device 20. Based on the detection information from the auger tilt angle detector 123, the auger tilt determination unit 103 of the controller 100 determines whether the tilt angle of the auger screw 25 exceeds the allowable angle. If the auger tilt determination unit 103 determines that the tilt angle of the auger screw 25 exceeds the allowable angle, it forcibly stops the rotation and vertical descent of the auger screw 25 (restricts the excavation operation of the auger screw 25). When the excavation operation of the auger screw 25 is restricted in this way, the worker operates the operating device 31 to vertically raise the auger screw 25, thereby pulling the auger screw 25 out of the ground (pillar hole). This allows the auger screw 25 to return to a state where it is suspended vertically downward from the tip of the boom 13 due to its own weight. Then, by rotating and vertically lowering the auger screw 25 again, and reinserting it into the excavated pole hole, a vertical pole hole can be formed.

[2. Pole erection work]
Next, the pole-erecting operation of the gripping-type hole-digging pole-erecting vehicle will be described. Figure 15 is a schematic diagram showing the operation of the gripping part 81 when the automatic vertical switch 34 is operated, and Figure 16 is a schematic diagram for explaining the direction of the load acting on the gripping part 81. Unless otherwise specified in the following description, the mode selection switch 33 will be assumed to be in normal mode.

When performing pole erection work with the gripping hole-digging pole-erecting vehicle 1, first, the operating device 31 is operated to appropriately move the boom 13, as well as the bending and extending of the arm 51, and the vertical, horizontal, and rotational movements of the gripping unit 81, thereby moving the gripping unit 81 close to the utility pole (for example, a utility pole placed horizontally at the work site) and aligning the gripping unit 81 with the utility pole. Next, the pair of gripping claws 82 are operated in the closing direction (closed operation) to grip the utility pole with the gripping unit 80. While the gripping unit 81 is gripping the utility pole in this state, the load acting on the gripping unit 81 is detected moment by moment by the gripping unit load detector 125, and this detection signal is input to the controller 100. Then, the boom 13 and gripping device 50 are operated appropriately to lift the utility pole gripped by the gripping unit 81 and move it above the pole erection hole (the pole erection hole excavated in the aforementioned excavation work). Above this pole installation hole, the operator operates the operating device 31 to visually bring the utility pole closer to a vertical position, as shown in Figure 15(A). Once the utility pole is in a somewhat vertical position, the operator turns on the automatic vertical switch 34. When the automatic vertical control unit 105 of the controller 100 receives an operation signal from the automatic vertical switch 123 and determines that the tilt angle of the gripping part 81 is within a predetermined angle, it outputs a command signal to the operation control unit 102. When the operation control unit 102 receives the command signal from the automatic vertical control unit 105, it operates the vertical swivel cylinder 62 to extend and retract based on the detection information from the gripping part tilt angle detector 124 to correct the tilt of the gripping part 81 in the front-to-back direction, and also operates the gripper motor 79 to rotate to correct the tilt of the gripping part 81 in the left-to-right direction, thereby bringing the gripping part 81 to a horizontal position. As a result, as shown in Figure 15(B), the utility pole gripped by the gripping part 81 can be brought into a vertical position. Furthermore, if the position (front, back, left, or right) of the vertically positioned utility pole and the pole installation hole are misaligned, the boom 13 can be extended and retracted and rotated to move the utility pole horizontally (front, back, left, or right) while maintaining its vertical position, thereby positioning the utility pole directly above the pole installation hole.

Next, in order to move the vertically positioned utility pole vertically downward toward the pole installation hole, the mode selection switch 33 is operated to switch from the normal mode to the gripping part vertical operation mode. As shown in Figure 16(A), when the gripping part 81 is gripping the vertically positioned utility pole, a load corresponding to the weight of the utility pole acts downward on the gripping part 81. Subsequently, after switching the mode selection switch 33 to the gripping part vertical operation mode, the luffing and raising operation of the boom 13 and the vertical swing operation of the gripping part 81 are linked in response to the operation of the boom slewing and luffing operation lever 32a, and the gripping part 81 is moved vertically downward, thereby inserting the utility pole gripped by the gripping part 81 into the pole installation hole. As the gripping part 81 is moved vertically downward, when the lower end of the utility pole gripped by the gripping part 81 comes into contact with the bottom of the pole installation hole, the gripping part 81 receives a ground reaction force (a force that pushes the utility pole upward) from the bottom of the hole via the utility pole. As a result, as shown in Figure 16(B), the load acting on the gripping portion 81 reverses from a downward direction to an upward direction. At this time, the load determination unit 106 of the controller 100 outputs a restriction signal to the operation control unit 102 when the load acting on the gripping portion 81 becomes zero, stopping the vertical downward movement of the gripping portion 102. Therefore, the vertical downward movement of the gripping portion 81 (utility pole) is stopped the moment the lower end of the utility pole contacts the bottom of the pole installation hole, and the utility pole is positioned relative to the pole installation hole. After inserting the utility pole to the bottom of the pole installation hole in this manner, the lower end of the utility pole can be embedded and compacted in the pole installation hole by filling the gap between the utility pole and the pole installation hole with soil or other materials (by backfilling with excavated soil or crushed stones). This completes the pole installation work of setting the utility pole into the pole installation hole.

[3. Column Removal Work]
Next, we will explain the pole removal operation (automatic pole removal operation) of the gripping-type hole-digging pole-erecting vehicle 1. Figures 17 to 19 are schematic diagrams showing the flow of the automatic pole removal operation.

First, to perform the automated pole removal operation, as shown in Figure 17(A), the pole removal machine 40 is set up near the base of the existing utility pole to be removed (indicated by the symbol "P" in Figures 17-19). The chain 45 of the pole removal machine 40 is wrapped around the pole several times, and both ends of the chain 45 are secured to the upper end of the pole removal machine cylinder 41. Furthermore, the hydraulic hoses 46 and 47 (see Figure 10) of the pole removal machine cylinder 41 are connected to the hydraulic outlet of the vehicle, connecting the pole removal machine cylinder 42 to the electromagnetic proportional control valve V10. Finally, the operating device 31 is operated to move the gripping part 81 to near the center of gravity of the utility pole, and then the gripping part 81 is operated in the closing direction to grip the center of gravity of the utility pole. This completes the preliminary preparation for the operation.

After completing the preliminary preparations for the work, the worker turns on the automatic pole removal switch 35 of the operating device 31. This causes the automatic pole removal control unit 107 of the controller 100 to start the automatic pole removal work according to a pre-stored automatic pole removal program. First, upon receiving the operation signal from the automatic pole removal switch 35, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the gripper cylinder 99 to extend and operate the gripping portion 81 (gripping claws 82) in the opening direction. This temporarily loosens the grip on the utility pole by the gripping portion 81, as shown in Figure 17(B). This opening operation (release operation) of the gripping portion 81 is performed by moving the pair of gripping claws 82 away from each other to the extent that the utility pole does not detach from the gripping portion 81, thereby weakening the gripping force of the gripping portion 81 on the utility pole (a small gap may be left between the gripping claws 82 and the utility pole at this time). The opening operation of the gripping portion 81 (extension operation of the gripper cylinder 99) is performed until the pressure detected by the gripper cylinder pressure detector 126 (pressure in the rod -side oil chamber of the gripper cylinder 99) falls below the second threshold pressure.

Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the pole removal machine cylinder 41 to extend, as shown in Figure 17(C). By extending the pole removal machine cylinder 41, the chain 45 of the pole removal machine 40 becomes taut (tightening the pole), and the pole is pulled out of the ground in response to the extension of the pole removal machine cylinder 41.

Next, the automatic pole removal control unit 107 determines whether the pole removal cylinder 41 has reached its fully extended state (the end of the stroke in the extension direction). Based on the detection information from the pole removal cylinder pressure detector 127, the automatic pole removal control unit 107 determines that the pole removal cylinder 41 has reached its stroke end (fully extended state) when the pressure in the bottom oil chamber of the pole removal cylinder 41 exceeds a predetermined pressure (maximum pressure). If the automatic pole removal control unit 107 determines that the pole removal cylinder 41 has reached its fully extended state, it outputs a command signal to the operation control unit 102, stopping the extension operation of the pole removal cylinder 41 and holding the pole removal cylinder 41 in the fully extended state for a predetermined time (for example, 1 second), as shown in Figure 18(D).

Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the gripper cylinder 99 to retract and the gripping portion 81 (gripping claws 82) to operate in the closing direction. As a result, the utility pole is gripped by the gripping portion 81, as shown in Figure 18(E). This closing operation of the gripping portion 82 (retraction operation of the gripper cylinder 99) is performed until the pressure detected by the gripper cylinder pressure detector 126 (pressure in the rod- side oil chamber of the gripper cylinder 99) becomes equal to or greater than the first threshold pressure (it is performed until the gripping force of the gripping portion 81 reaches a specified gripping force).

Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the pole removal machine cylinder 41 to retract, as shown in Figure 18(F). By retracting the pole removal machine cylinder 41, the tension of the chain 45 is gradually released, allowing the pole removal machine cylinder 41 to retract while the pole is held in place by the gripping unit 81 (in a state where the pole is held to prevent it from falling).

Next, the automatic pole removal control unit 107 determines whether the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction). Based on the detection information from the pole removal machine cylinder pressure detector 128, the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction) when the pressure in the rod-side oil chamber of the pole removal machine cylinder 41 exceeds a predetermined pressure (maximum pressure). If the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction), it outputs a command signal to the operation control unit 102, stopping the retraction operation of the pole removal machine cylinder 41 as shown in Figure 19(G), and holding the pole removal machine cylinder 41 in the fully retracted state. Then, if the worker confirms that the base of the utility pole is loose, the automatic pole removal operation ends when the automatic pole removal switch 35 of the operating device 31 is turned off, completing one cycle of the operations up to this point.

Once the automatic pole removal operation is complete, the pole removal machine 40 is removed from the utility pole as shown in Figure 19(H). Next, as shown in Figure 19(I), the operator uses the control device 31 to appropriately operate the boom 13 and gripping device 50, moving the gripping section 81 upwards. This lifts the utility pole, gripped by the gripping section 81, through the pole-mounting hole and moves it to the designated location. After lowering the utility pole at the designated location, the gripping claws 82 are opened, releasing the grip on the utility pole from the gripping section 81, allowing the utility pole to be placed in the designated location.

Although not shown in the diagram, if the automatic pole removal switch 35 is not switched from on to off within a predetermined time (for example, 10 seconds) after the completion of the first cycle of the automatic pole removal operation, the second cycle of the automatic pole removal operation will start (if the automatic pole removal switch 35 is not switched from on to off, the operation can continue for the third cycle and beyond). In other words, if the utility pole cannot be pulled out in only one cycle of the automatic pole removal operation (if the base of the utility pole does not loosen), if the automatic pole removal switch 35 is left on, the second and subsequent cycles of the automatic pole removal operation will start automatically (the automatic pole removal operation will be automatically repeated). In the second and subsequent cycles of this automatic pole removal operation, in order to prevent the utility pole to be removed from falling from the gripping part 81, the gripping part 81 is held in a closed state until the detected pressure of the pole removal machine cylinder pressure detector 127 (pressure in the bottom oil chamber of the pole removal machine cylinder 41) reaches a predetermined value, and when the detected pressure reaches the predetermined value, the gripping part 81 is operated in the opening direction. In other words, in the first cycle of the aforementioned automatic pole removal operation, the extension of the pole removal machine cylinder 41 was initiated after the gripping part 81 was opened (after the gripping part 81 released its grip). However, in this second cycle, the extension of the pole removal machine cylinder 41 is initiated first, and after the pressure detected by the pole removal machine cylinder pressure detector 127 reaches a predetermined value, the gripping part 81 is opened (the grip is released). This prevents the utility pole from falling during the removal process.

The main effects achieved in this embodiment can be summarized as follows:

First, according to this embodiment, if the auger screw 25 tilts in any direction (forward, backward, left, or right) beyond the allowable angle relative to the vertical, the operation of the boom 13 and the auger screw 25 can be restricted, automatically stopping the excavation work of the auger screw 25. This prevents the hole for erecting utility poles from being formed at an angle relative to the vertical.

Furthermore, according to this embodiment, when moving the gripping portion 81 downwards to insert the utility pole held by the gripping portion 81 into the pole-mounting hole (a hole for erecting a columnar object), if the load acting on the gripping portion 81 drops below a threshold load, it is determined that the lower end of the utility pole has come into contact with the bottom of the pole-mounting hole. The downward movement of the gripping portion 81 (utility pole) is then automatically stopped. This prevents the worker from continuing to move the gripping portion 81 downwards without noticing that the lower end of the utility pole has come into contact with the bottom of the hole (resulting in the lower end of the utility pole being excessively pressed against the bottom of the hole), thus preventing excessive load from being applied to the gripping portion 81 or the utility pole, which could lead to damage.

Furthermore, according to this embodiment, when the automatic vertical switch 34 is operated, the vertical swivel cylinder 62 and gripper motor 79 are activated according to the inclination angle of the gripping part 81 relative to the horizontal plane detected by the gripping part inclination angle detector 124, thereby changing the posture of the gripping part 81. This allows the utility pole gripped by the gripping part 81 to be positioned vertically. Therefore, even on sloping ground such as in mountainous areas, the utility pole gripped by the gripping part 81 can be automatically positioned vertically without requiring skilled operation, dramatically improving the efficiency of pole erection work.

Furthermore, in this embodiment, control is performed to position the utility pole held by the gripping part 81 vertically only when the inclination angle of the gripping part 81 with respect to the horizontal plane, as detected by the gripping part inclination angle detector 124, is within a predetermined angle. This limits the range of motion required to change the gripping part 81 to a vertical position, preventing the utility pole from interfering with surrounding structures or the ground, or coming into contact with workers, thereby ensuring work safety.

Furthermore, according to this embodiment, there is no need to use large heavy machinery such as cranes to lift the utility poles to be removed. The gripping device 50 of the gripping-type hole-digging and pole-erecting vehicle 1 can appropriately switch between gripping and releasing (releasing the grip) the utility poles to be removed, allowing the pole removal work to be performed by the pole removal machine 40. Therefore, a single gripping-type hole-digging and pole-erecting vehicle 1 can perform different types of work (pole erection and pole removal), expanding the applications of the gripping device 50 and further increasing the added value of the gripping-type hole-digging and pole-erecting vehicle 1.

Furthermore, in this embodiment, the opening and closing operation of the gripping section 31 and the extension and retraction operation of the pole removal machine 40 are combined in an interlocking operation, allowing a series of pole removal operations to be performed automatically and continuously. This reduces the effort and burden on the worker, thereby improving the efficiency and safety of the pole removal work.

Furthermore, in this embodiment, even if the utility pole cannot be pulled out in a single extension/retraction operation of the pole removal machine 40, the pole removal machine 40 can be automatically and continuously performed multiple extension/retraction operations in response to the operation of the automatic pole removal switch 35, thereby further improving the work efficiency of the pole removal operation.

Furthermore, the present invention is not limited to the embodiments described above, and modifications can be made as appropriate without departing from the spirit of the invention.

In the above embodiment, the gripping load detector 125 is configured as a pin-type load cell that detects the load acting on the connecting pin 63. However, the configuration is not limited to this. For example, the gripping load detector 125 may be configured as a pressure detector that detects the pressure of the hydraulic fluid supplied to the bottom-side oil chamber and/or rod-side oil chamber of the vertical swivel cylinder 62.

In the above embodiment, the gripping force of the gripping portion 81 (the force with which the gripping claws 82 grip the object) is indirectly detected based on the pressure in the rod -side oil chamber of the gripper cylinder 99. However, the configuration is not limited to this, and for example, the gripping force of the gripping portion 81 may be directly detected by providing a load cell or strain gauge inside the gripping claws 82.

In the above embodiment, the stroke end in the extension/retraction direction of the column removal machine cylinder 41 was detected by the pressure in the bottom-side oil chamber and the rod-side oil chamber of the column removal machine cylinder 41. However, the configuration is not limited to this, and for example, it may be configured using a stroke detector that detects the position (stroke position) of the piston rod 43 of the column removal machine cylinder 41 in the extension/retraction direction.

In the above embodiment, the operating device 31 is provided on the operating seat 30 on the vehicle body 2. However, the configuration is not limited to this, and for example, the operating device 31 may be configured as a wired or wireless remote control operating device (portable operating device).

Furthermore, while the above embodiment illustrates a PTO-driven hole-digging and pole-erecting vehicle that uses engine power via a PTO (power take-off) mechanism to drive a hydraulic pump, the configuration is not limited to this. An electric-driven (battery-driven) hole-digging and pole-erecting vehicle or a hybrid vehicle equipped with both, selectively switching between power sources, may also be used.

1. Gripping-type hole-digging and pole-erecting vehicle 2. Vehicle body 12. Turntable 13. Boom 20. Auger device 22. Auger motor 25. Earth auger 31. Operating device 33. Mode selection switch 34. Automatic vertical switch 35. Automatic pole removal switch 40. Pole removal machine 41. Pole removal machine cylinder 50. Gripping device 51. Arm 55. Arm cylinder 60. First joint member 62. Vertical swivel cylinder 70. Second joint member 71. Horizontal swivel cylinder 79. Gripper motor 80. Gripper 81. Gripping part 82. Gripping claws 99. Gripper cylinder 100. Controller 101. Position calculation unit 102. Operation control unit 103. Auger tilt determination unit 104. Gripping determination unit 105. Automatic vertical control unit 106. Load determination unit 107. Automatic pole removal control unit 123. Auger tilt angle detector 124. Gripping part tilt angle detector 125. Gripping part load detector 126. Gripper cylinder pressure detector 127. Pole removal machine cylinder pressure detector 128 Pole removal machine cylinder pressure detector

Claims (2)

A boom mounted on the vehicle body that can be raised and lowered and extended,
A gripping part for gripping a columnar object,
A support mechanism is provided between the tip of the boom and the gripping portion to change the orientation of the gripping portion relative to the tip of the boom,
A gripping portion tilt angle detector for detecting the tilt angle of the gripping portion with respect to the horizontal plane,
An operating device for operating the boom, the gripping part, and the support mechanism,
The system includes an operation control unit that controls the operation of the boom, the gripping part, and the support mechanism in accordance with the operation of the operating device,
The operating device has an automatic vertical operating device for positioning the columnar object gripped by the gripping part in a vertical orientation.
The control device for a gripping -type hole-digging and pole-erecting vehicle is characterized in that, when the automatic vertical operation device is operated and the angle of inclination of the gripping part with respect to the horizontal plane detected by the gripping part inclination angle detector is within a predetermined angle, the operation control device operates the support mechanism in accordance with the angle of inclination of the gripping part with respect to the horizontal plane detected by the gripping part inclination angle detector to change the posture of the gripping part, thereby controlling the columnar object gripped by the gripping part to be in a vertical position. The gripping portion has a pair of openable and closable gripping claws for gripping a columnar object.
The support mechanism includes a swivel mechanism that causes the gripping portion to swing within a vertical plane, and a rotation mechanism that causes the gripping portion to rotate within the vertical plane around a rotation axis perpendicular to the opening and closing direction.
The control device for a gripping-type hole-digging pole-erecting vehicle according to claim 1, wherein the operation control unit operates the swivel mechanism according to the angle of inclination of the gripping part in the rotation axis direction relative to the horizontal plane, as detected by the gripping part inclination angle detector, and operates the rotation mechanism according to the angle of inclination of the gripping part in the opening and closing direction relative to the horizontal plane, thereby changing the posture of the gripping part and making the columnar object gripped by the gripping part into a vertical position.